A £6million arrival from Olympiakos last summer, the Belgium international has shone at times.
His brilliant match-winner against Stoke last weekend was an obvious example of Mirallas' class, taking him up to six goals for the season.
However, the 25-year-old has also been limited to 25 games for the Toffeemen after being struck down by hamstring and groin complaints.
It is a groin injury sustained against Stoke that makes Mirallas a doubt for Sunday's trip to fellow Champions League contenders Tottenham.
With Marouane Fellaini and Steven Pienaar already ruled out through suspension, Moyes is crossing his fingers another key figure in his squad does make it.
Whether that comes to pass or not, the Everton chief is convinced Mirallas will be a better player for this season's experiences.
"Kevin is coming to terms with a groin strain but hopefully he will have a good chance," said Moyes.
"But generally he is finding the whole Premier League a strain. Quite regularly he is struggling to complete games.
"Hopefully he will be better for it next year and he will understand the level of fitness that is going to be required because he has the ability to win us games."
Crowned manager of the month for March after three straight wins at Goodison Park, Moyes' team must maintain their winning form if they are to retain any chance of sneaking into a Champions League berth.
With trips to Arsenal and Chelsea still to come, Moyes knows it is not going to be easy.
However, a win at White Hart Lane would reduce the gap on their hosts to just three points, with their task made significantly easier by the almost certain absence of Gareth Bale, who was carried off with an ankle injury towards the end of last night's Europa League encounter with FC Basel.
"We are moving to Plan B," said the Scot.
"It is unfortunate. We don't want good players to be out because they are what makes the Premier League so special.
"But when you are the opposing manager against arguably the best player in the league at this moment in time, it is not a bad thing to have him out."
Bale's injury is a reminder of the increased demands European football can bring.
It is where Moyes wants to manage though. And a plan is already formulating in his mind about how to deal with it.
"You hear me keep talking about how much I want to be back in Europe all the time," he said.
"Europe does take its toll in league fixtures and if we made it, we would have to find a way of dramatically getting more players into our squad.
"But it can galvanise your club as well.
"Tottenham have had some unbelievable results in Europe and some great nights. Think about their games against Inter Milan.
"Unfortunately Tottenham have lost a couple of players to injury. But that can happen to anyone."